Resin compositions for producing biaxially oriented polypropylene films

Abstract

Polypropylene resin compositions are provided that are useful in the production of biaxially oriented polypropylene films (BOPPs). The resins of the present invention are blends of high crystalline (low solubles) polypropylene homopolymer and an ethylene/propylene random copolymer (RCP). These blends can be used to replace standard high solubles BOPP grade polypropylene homopolymers. In addition, the use of high crystalline polypropylene homopolymers in the blends imparts improved stiffness to the finished films while maintaining good processability of the blends.

What is claimed is:  
     
       1. A biaxially oriented polypropylene film comprising: 
       about 70% to about 95% by weight of a polypropylene homopolymer, said polypropylene homopolymer having less than 3% by weight xylene solubles; and  
       about 5% to about 30% by weight of an ethylene/propylene copolymer, said ethylene/propylene copolymer containing from about 0.5% to about 7% ethylene by weight.  
     
     
       2. The biaxially oriented polypropylene film according to  claim 1 , wherein said polypropylene homopolymer has a crystallinity of at least 55%. 
     
     
       3. The biaxially oriented polypropylene film according to  claim 1 , further comprising at least one additive selected from the group consisting of: nucleators, anti-oxidants, acid neutralizers; slip agents, antiblock, antifogging agents and pigments. 
     
     
       4. The biaxially oriented polypropylene film according to  claim 1 , wherein said composition comprises about 70% to about 85% of a polypropylene homopolymer having less than 3% by weight xylene solubles, and 
       about 15% to about 30% by weight of an ethylene/propylene copolymer, said ethylene/propylene copolymer containing from about 0.5% to about 7.0% ethylene by weight.